RESUMEN
The involvement of brain cytosolic androgen receptors in the female-induced increase in scent-marking behavior of male Mongolian gerbils was studied. Scent-marking activities and serum testosterone concentrations were measured in low-marking control males and in males with increased scent-marking activities, stimulated by the presence of conspecific females in the same room. For every individual male the concentrations and affinities of androgen receptors were determined in four parts of the brain, which contained the hippocampus, septum, corpus striatum, amygdala, stria terminalis, and the hypothalamus. Compared to the basal unstimulated period, the marking activities of male gerbils significantly increased 58% during the presence of female conspecifics in their housing room. The serum testosterone concentrations did not change significantly during female presence. The association constants of the cytosolic androgen receptors were higher in the female-stimulated males compared to isolated control males. In contrast, the cytosolic receptor concentration was reduced. The difference reached significance in one of the brain parts. Individual levels in scent-marking activities could not be explained by correlation with individual androgen receptor parameters. The present results suggest that increased androgen binding in the brain may be involved in the elevation of scent-marking activities in male gerbils, caused by urinary chemical signals of female conspecifics.
Asunto(s)
Neuronas Aferentes/fisiología , Receptores Androgénicos/fisiología , Conducta Sexual Animal/fisiología , Andrógenos/metabolismo , Animales , Encéfalo/anatomía & histología , Química Encefálica/fisiología , Citosol/metabolismo , Femenino , Gerbillinae , Masculino , Proteínas del Tejido Nervioso/metabolismo , Testosterona/sangreRESUMEN
This paper describes a mathematical model for the quantification of receptors based only upon the total bound values as a function of the total ligand concentration. In contrast to methods relying on linearization transformations, this nonlinear model requires more sophisticated computation, however, avoids loss of material for determination of nonspecific binding in competed tubes. Monte-Carlo simulation indicated high stability of this model against random experimental error. The androgen receptor of the male gerbil (Meriones unguiculatus) ventral prostate is characterized using the described nonlinear computation.